J. M. Elliott

Energy equivalents of oxygen consumption in animal energetics

SummaryThe energy equivalents given in the literature are reviewed and criticised. New equivalents are calculated for protein respiration.The energy equivalent for converting rate of oxygen consumption into rate of heat production (Qox cal mg-1 oxygen consumed) is 3.53 cal mg-1 for carbohydrate oxidation, 3.28 cal mg-1 (range 3.22–3.32) for fat oxidation. Qox values for the respiration of standard protein are the same at 3.25 cal mg-1 for ureotelic and uricotelic animals, and about 2% less at 3.20 cal mg-1 for ammoniotelic animals. The energy equivalent for converting rate of oxygen consumption into rate of energy loss in excreta (Qex cal mg-1) varies considerably with different excretory products. Values for standard protein are 0.62 cal mg-1 for ammonioteles, 0.58 cal mg-1 for ureoteles, and 0.94 cal mg-1 for uricoteles.The various factors affecting both Qox and Qex are discussed, and examples of the estimation of general energy equivalents are given.

The distances travelled by drifting invertebrates in a Lake District stream

SummaryThe distances travelled by drifting invertebrates of 18 taxa were investigated at sites 3 and 4 in the Wilfin Beck, a small stony stream in the English Lake District. Fifty invertebrates of the same taxon were released into the stream at increasing distances upstream from a large net which caught all invertebrates drifting downstream.The relationship between the catch in the net (Yx) and the distance from the release point to the net (X m) was well described by the regression equation:n

Life histories and drifting of the Plecoptera and Ephemeroptera in a Dartmoor stream

Y_x = Ae^{ - RX}

The effects of electrofishing on the invertebrates of a Lake District stream

n whereR is the constant relative rate of return of invertebrates to the bottom of the stream, andA=Y0=number of invertebrates released at each point=50. Values ofR, the mean drift distance (n

The daily activity patterns of mayfly nymphs (Ephemeroptera)

bar X

Eggs of Ephemeroptera

n m), and the distance (Xp m) travelled byP% (1%, 10%, 50%) of the drifting invertebrates were calculated for each taxon at different modal water velocities. Values ofR,n